Tab Controls - How do I know which tab I am going to while still on the current tab?

[Brian Schmidt]

I have a windows form with three tabs. In the instance where a
specific one is selected, I need to do some validation to determine if
the user may navigate to one of the other two, but not when navigating
to the other of the two.

Here's the scenario:
I have tabs A, B and C. When the user is on tab B and wish to go to
tab C, I need to run some validation to determine if I can allow them
to do that. However, they may navigate to tab A at anytime. So, I am
intersted in knowing how to identify, while tab B is still 'selected',
during the validating event of tab B, to which tab I will then be
navigating. Is there an attribute on the tab control that will tel me
this, or something to that effect? Any help would be appreciated.

[Fergus Cooney]

Hi Brian,

I don't know about you, but any time a program lets me do something and
then tells me off when I dare to do it, I send a curse through the ether to
the programmer. If there are a lot of things like that in a program then it
finds itself teetering on the edge of the Recycle Bin - like Homer and the
Black Hole - what an episode!! ;-))

Prevention beats a curse - if Tab C is off-limits when on Tab B, disable
it.

If this is a dynamic property, dependant on what the User is doing while
on Tab B, enable and disable Tab C as required. If nothing else this will
teach the User the effect of their actions.

Unfortunately, that doesn't stop the User from clicking on the TabPage,
it disables the Controls on it. So to give some indication that this is the
case, you could enclose the TabPage caption in brackets, or set it to lower
cse or something.

The code below shows you two ways to do this. The first removes and adds
brackets as required. The second saves the existing caption in the TabPage's
Tag property.

Regards,
Fergus

<code>
'Encloses the TabPage's caption in brackets when disabled.
Public Sub SetTabPageEnable (PageIndex As Integer, IsEnabled As Boolean)
With TabControl1.TabPages (PageIndex)
.Tag = .Text
Dim sCaption As String = .Text
If sCaption.Substring (0, 1) = "(" Then
sCaption = Mid (sCaption, 2, Len (sCaption) - 2)
'or
sCaption = sCaption.Substring (1, sCaption.Length - 2)
End If
If IsEnabled = False Then
sCaption = "(" & sCaption & ")"
End If

.Enabled = IsEnabled
.Text = sCaption
End With
End Sub

'This assumes that the TabPage will be disabled before it is
're-enabled. so the Tag property will be valid.
'Encloses the TabPage's caption in brackets when disabled.
Public Sub SetTabPageEnable (PageIndex As Integer, IsEnabled As Boolean)
With TabControl1.TabPages (PageIndex)
.Enabled = IsEnabled
If IsEnabled Then
.Text= .Tag
Else
.Tag = .Text
.Text = "(" & .Text & ")"
End If
End With
End Sub
</code>

[Herfried K. Wagner [MVP]]

* bs**********@aol.com (Brian Schmidt) scripsit:

I have a windows form with three tabs. In the instance where a
specific one is selected, I need to do some validation to determine if
the user may navigate to one of the other two, but not when navigating
to the other of the two.

Here's the scenario:
I have tabs A, B and C. When the user is on tab B and wish to go to
tab C, I need to run some validation to determine if I can allow them
to do that. However, they may navigate to tab A at anytime. So, I am
intersted in knowing how to identify, while tab B is still 'selected',
during the validating event of tab B, to which tab I will then be
navigating. Is there an attribute on the tab control that will tel me
this, or something to that effect? Any help would be appreciated.

See:

<http://groups.google.com/groups?selm=hxAg9.261485%24kp.887854%40rwcrnsc52.o ps.asp.att.net>

--
Herfried K. Wagner
MVP · VB Classic, VB.NET
<http://www.mvps.org/dotnet>